You have two options here:
1. Create an extract data source and publish it to tableau server with an refresh schedule of your choice. You will need to have an admin create a "schedule" that matches your need before setting it as your schedule. You then create a datasource connection from your workbook to the published data source.
2. Connect your workbook to the Live data source (as you desire).
In either case, you are defining a new data source (either published extract or live), and will need to "swap" out the current data source to the new one. To do that you have both data sources (the current, and the new) defined in the workbook, and go to "Data->Replace Data Source" menu item and swap them out.
If you are concerned about this process, create a back up of your workbook, and then follow these steps. You should not have concerns of "undoing all the work".
Thank you for your help. I used the first option and it worked out fine.